//SamXIAO
#include <bits/stdc++.h>
using namespace std;
#define PI 3.1415926
#define   SQUARE(x) ((x)*(x))
//double SQUARE(double x) { return x*x;}
#define N_MAX 987654321
#define N_MIN -N_MAX
int f1[286][102];
char ss[1086];

void w1()
{
	int cnt = 0, ans = 0;
	char ch = getchar();
	while(isprint(ch)){
		if('0' <= ch && ch <= '9') cnt++;
		ch = getchar();
	}
	printf("%d", cnt);

}

int main()
{
	w1();
  return 0;
}
